DE2422469A1 - SULFUR EMULSION IN BITUMES - Google Patents

Description

PATENT ADVOCATE BORO TlEDTKE - BuilLING - KlNNE

TEL. (089) 53 9853-56 TELEX: 524845 tlpat CABLE ADDRESS: Germaniapatent Munich

8000 Munich 2 Bavariaring 4 9; May 1974

P.O. Box 202403 B 6011

Societe Nationale des Petroles D'Aquitaine Courbevoie, France

Sulfur emulsion in bitumen

The present invention relates to a new process for the production of sulfur emulsions in asphalt, bitumen, Tar or similar hydrocarbon material. She stretches also relate to new stable masses of sulfur finely dispersed in these materials.

The introduction of sulfur in bitumen, asphalt, tar or bad luck has long been practiced, and it has been denied. different compositions of coal-like masses with sulfur described in the literature. One of their main uses is road paving, whose properties are characterized by the presence of the Sulfur can be improved. Generally there will be three

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Types of such masses described: Some experience a modification by chemical action after forced heating of sulfur; the others contain a solution and / or dispersion of sulfur particles in the hydrocarbon mass; if finally the sulfur content is far from that of the asphalt exceeds, there is a coarse dispersion of hydrocarbon material and sulfur before. According to these authors, the better mechanical and rheological properties are obtained if the sulfur content ranges from about 10 to 400 percent based on the weight of the hydrocarbon material. For example can be found in the French patent specification

1 444 629 information according to which the load-bearing capacity of a road surface is increased considerably when the sulfur / bitumen weight ratio reaches 2.2. Similar results can be found in French patent specification 71 35808. In contrast, the American patent recommends

2,182,837 primarily related to sulfur contents of 33 to 100% on bitumen.

The applicant's work shows that the contradictions between the various results of the prior art Technology and the dispersion of the mechanical and rheological properties found largely depend on the heterogeneity originates from the masses used so far. It was found that in a bituminous one made with more than 15% sulfur The precipitation of sulfur from the mass in the course of long times is favored, which leads to a decrease in the mass

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mechanical properties of the covering leads. During about 15 Wt .-% sulfur remains dissolved in the hydrocarbon material, the excess sulfur can only be present in the form of a dispersion or, if appropriate, in supersaturated form. The contribution the sulfur in the hydrocarbon material takes place in heat, and that in supersaturation or in more or less Sulfur present in imperfect dispersion undergoes physical transformations during cooling. This explains the unfavorable changes that occur in the course of the aging of the known masses. This is why rubbers based on bitumen and sulfur with a high sulfur content so far are unsatisfactory.

According to the present invention, no very large amounts of sulfur are incorporated into the carbonaceous materials, such as bitumen, asphalt, tars, etc., but this non-metal must be dispersed as completely as possible in the form of particles which do not exceed 10 μ. According to the present invention, therefore, one actually obtains a fine emulsion of liquid sulfur in the liquid or pasty hydrocarbon material.

If the above conditions are observed, the masses obtained are very homogeneous and they show im In contrast to the well-known products, a surprising one for a long time Stability over a wide temperature range. It is found that the dispersions produced according to the invention

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-Frosted visions many times without any change, cooled, then reheated and re-softened. Without developing hydrogen sulfide, you can i.e. without dehydration of the bitumen by the sulfur, can be handled at 150 ° C. These products therefore show reproducible results Properties that are analogous to those of sulfur-free bitumen.

On the other hand, the emulsions of the invention show the advantage that ihe viscosity at about 140 ⁰ C is lower than that they can therefore be handled more easily of the pure bitumen, and. In contrast to the known products, the dispersions according to the invention do not separate the sulfur in the solid state after 3 years.

Another very important advantage of the new masses is their increased resistance to lane formation compared to a bituminous concrete with the same grain size curve. The invention Emulsions are particularly suitable for the production of bituminous road surfaces. They also allow that Production of excellent coverings with Weieh bitumina (penetration e.g. 80-100, 100-120 or 120-200), i.e. with bitumina that are suitable for numerous classic applications are too fluid. Thus, the invention allows the bitumens with increased penetration to Production of compact bituminous concretes can be used, which have the same properties as classic concrete with bitumen.

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show ringer penetration (20-30). The usual application of these latter concretes is much more difficult (200 ° C) than that of the new products according to the invention made from bitumens with strong penetration (140 ° C). As you can see, the advantages of the products according to the invention are due to that they are more flexible in the heat, but harder in the cold than ordinary bitumens of poor penetration.

Although the ratio of sulfur to the hydrocarbon material can vary widely according to the invention, this ratio is preferably 15 to 100 parts by weight per 100 parts of hydrocarbon material, and in particular about 20 to 45 parts by weight per 100 parts of hydrocarbon material.

As indicated above, the dispersed sulfur particles must have an average size equal to or equal to is less than 10 u. It is an advantage if they are as small as possible; in practice, however, it is sufficient that it is between 0.5 and 5 u lie.

To obtain a sulfur emulsion in a hydrocarbon material such as bitumen, asphalt, etc., subjects a mixture of molten sulfur with hydrocarbon material of a dispersion agitation. So that the sulfur liquid you have to work above 120 ° C of course.

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The upper temperature limit is determined by the type of hydrocarbon material and the transition temperature at which the liquid sulfur becomes very viscous (u-sulfur). In practical sulfur dispersions in road bitumen emulsification 125-200 ⁰ C can be performed, the preferred intermediate temperature is about 130 to 17Q ° C, and particularly at 150 to 160 ° C.

To the degree of forced dispersion required according to the invention To achieve this, one can use suitable apparatus for the liquid emulsification. In the present invention has however, such emulsification has been found to be quite difficult. The emulsification could be carried out using a conventional Turbine can be achieved, provided that it is brought into a certain special shape.

According to one embodiment of the invention, the sulfur emulsion is formed in the bitumen in such a way that a Sulfur / bitumen mixture is sent into a turbine, the gap between 0.1 and 2.25 mm, in particular between 0.4 and 1.15 mm, wide. To achieve optimal results, the gap width must also depend on the sulfur / bitumen ratio be regulated.

In general, the larger the proportion of sulfur to be dispersed, the larger the gap chosen. It is

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advisable on the one hand the speed of rotation of the turbine and on the other hand to regulate the gap width in such a way that the compression in the gap does not reach the value at which the Sulfur converts to U-sulfur. In other words, lower speeds are required for smaller gap widths and vice versa.

Excellent results were obtained with a Moritz type BF 50V turbine with an adjustable gap and a grinding cone speed of 7400 revolutions per minute will. Very stable emulsions with 13 to 25 parts of sulfur per 100 parts were obtained with gap widths of 0.3 to 0.5 mm Bitumen (penetration 80-100).

According to one embodiment of the invention, a sulfur / bitumen mixture is first placed in an apparatus that has a causes strong dispersion, e.g. in a turbo emulsifier, and the dispersion obtained is treated in a turbine with an expediently adjustable gap; the operation of the Turbine is made easier. Of course you can send an emulsion through the turbine several times if necessary, to achieve the desired degree of dispersion, i.e. the desired fineness of the sulfur droplets. For this purpose, the inventive The method takes place in a plurality of turbines or turbines and turbo emulsifiers connected in series.

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In the examples described below, which do not limit the invention, the Moritz turbine type BF 50V with an adjustable gap and a capacity of 3 liters was used. The turbine was driven by a motor with 1.75 hp. The speed of the grinding cone was adjustable from 7,000 to 13,000 revolutions / minute. The bitumen and sulfur were fed into the rotating turbine at the same time in the desired ratio. The temperature at the entrance to the Trbine was 140 to 190 ° C _f according to the tests, while the exiting product had a temperature of 110 to 140 ° C. The mean value between the inlet temperature and the outlet temperature is regarded as the working temperature defined above. The exiting product was returned to the turbine inlet so that it was subjected to the emulsifying action for a period of 3 minutes.

In other examples, the above-mentioned turbine was charged with a mixture of sulfur and bitumen that was previously used was emulsified for 3 minutes in a Moritz turbo emulsifier. In this case there was no more repatriation, but a single passage through the turbine BF 50 V. In the following, the sulfur is denoted by S and the bitumen by B.

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example 1

Changes in the viscosity of bitumen / sulfur mixtures A series of samples of the emulsion of sulfur (I to IV) in bitumen of penetration 80-100 is made in the Moritz turbine described above with a gap of 0.56 mm between and 120 ^° C her.

On the other hand, the bitumen alone (VI) is sent through the turbine under the same conditions. To the received Products and a sample mixture (V), which by simply stirring 33.3 parts of molten sulfur with 100 parts of the same bitumen had been prepared between 120 and 160 ° C, the viscosities were measured. The results, in particular the logarithm of the viscosities in cps are given in Table 1 below.

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Table 1

S / 100B 80 ° C 120 ° C 160 ° C

I Emulsion 11 3.45 2.66 1.90

II "25 4.04 2.76 1.78

III "33.3 4.32 2.83 1.86

IV "43 4.65 2.90 1.92

V Mixture according to prior art 33.3 3.62 2.97 2.29 ⁺

VI bitumen alone O 3.93 2.9V 2.33

The mix is heterogeneous.

It is interesting to note that the viscosities of the inventive emulsions I to IV depending on the Temperature vary much more than the viscosity of bitumen alone and the viscosity of a bitumen / sulfur mixture According to the state of the art. Indeed, it can be seen that the mass in emulsions II to IV, i.e. more than 11 parts sulfur to 100 parts bitumen, in which cold (viscosity at 80 ° C is much higher) is much harder than the prior art mixture V and the bitumen VI alone. In contrast, the viscosity is that according to the invention Emulsions I to IV at higher temperatures, especially at about 160 ° C, where the shaping of the bituminous masses takes place, much lower than the viscosity of the known

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Mixture or bitumen alone. From this follows an easier one Processability in the heat with a better behavior in the cold.

With the same products as those of Example 1, the however, they were first treated for 3 minutes in a Moritz turbo-emulsifier and then sent to a BF 50 V turbine the results are of the same order of magnitude as those in Table 1, with the difference in the case of the emulsions according to the invention between 80 and 160C is even more pronounced.

Example 2
Cohesion of the sulfur / bitumen masses

In a number of samples according to the invention such as

shown in example 1, but with a gap of 0.4 mm

ten emulsion, the cohesiveness was determined in kg / cm. Table 2 contains the values found for -30 ⁰ C, +5 ⁰ C and +55 ⁰ C.

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S / 10OB

- 12 -

Table 2

-33 ⁰ C

0 0.28 5.25 0.32 11, 0 0.46 17.7 1, 24 25.0 0.68 33.3 0.92 43.0 1, 10 " Dimensions
after the
technology 0.43

₊ 5 ° C

1.58 1.25 1.23 2.00 1.86 2.56 1.99 1.73

+55 ⁰ C

2.25 2.64 6.12 6.32 5.72 4.42 5.67 4.26

It can be seen that the property of the compositions according to the invention is significantly improved in relation to that of bitumen without the addition of sulfur and in relation to a composition according to the prior art. This improvement is particularly noticeable with sulfur contents over 11% based on bitumen. This advantage is at very low temperatures (-33 ⁰ C) as well as for summer temperatures in the order of 55 ° C,
which road surfaces are often exposed, very significant.

Example 3

Cohesion depending on the gap width in the turbine

The experiments given in Table 2 at -33 C with

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the emulsions according to the invention were repeated with emulsion samples which were produced in the same turbine with variable gap widths. Below are the ones found Cohesivities indicated.

Table 3 0.4 mm 1.15 mm Gap width 0.46 0.56 S / 100B 0.15 mm 1, 24 0.90 11 0.27 0.92 0.90 17.7 0.77 1.10 • 0.63 33.3 0.85 43.0 • 0.39

It can be seen that the maximum cohesiveness for emulsions 17 to 43 parts of sulfur per 100 parts of bitumen with a gap width of 0.4 mm. In contrast, it seems with 11 parts of sulfur, the most favorable gap width is 1.15 mm. Thus, according to the invention, forms the appropriate one Controlling the gap width for a given emulsion is actually an important factor.

Briefly summarized, the invention relates to a method for dispersing molten sulfur in a hydrocarbon material such as asphalt, tar and especially bitumen. The dispersion takes place in such a way, that there is an emulsion of very fine sulfur particles of sizes not exceeding 10 µ in the hydrocarbon material manufactures. For this purpose a turbine with a gap width of

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about 0.1 to 2.25 mm very suitable. The emulsions obtained are particularly suitable for road surfaces.

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Claims (12)

2422A69 claims 1. A process for the preparation of emulsions of sulfur in a hydrocarbon material of the class of bitumens, asphalts and tars, by stirring the molten sulfur with the hydrocarbon material, characterized in that the stirring is carried out in such a way that the sulfur droplets dispersed in the hydrocarbon material the Do not exceed a size of 10 u, in particular its mean size is in the range from about 0.5 to 5 yes. 2. The method according to claim 1, characterized in that that the emulsion is prepared by passing a mixture of molten sulfur with bitumen through a turbine sends, the gap of which is 0.1 to 2.25 mm, preferably 0.4 to 1.15 mm, wide. 3. The method according to claim 1 or 2, characterized in that the emulsification at a temperature of 125 to 200 ° C, preferably carried out between about 130 ° and 170 ⁰ C it. 4. The method of claim 2 or 3, characterized in that introducing the mixture at a temperature of about 140 to 1.60 ⁰ C in the turbine and the mixture having about TTO to 140 ° C from the turbine outlet. Ά 09850/0763 - 46 - 5. The method according to any one of claims 2 to 4, characterized in that the mixture is repeated several times through the same turbine or through several successive, turbines arranged in series. 6. The method according to any one of claims 1 to 5, characterized in that the mixture of sulfur and bitumen first subjected to a first dispersion, in particular in a turbo-emulsifier or turbo-reactor, and the product formed is then treated in a turbine with a gap of 0.1 to 2.25 mm. 7. mass of a mixture of sulfur with a hydrocarbon material from the class of bitumina, Asphalts and tars, characterized in that the sulfur is in the form of particles whose sizes do not exceed 10 ji and which are dispersed in the hydrocarbon material. 8. Composition according to claim 7, characterized in that the mean dimensions of the sulfur particles in the Range from about 0.5 to 5 U. 9. Composition according to claim 7 or 8, characterized in that that the proportion of sulfur is 15 to 100 parts by weight, preferably 20 to 45 parts per 100 parts of hydrocarbon material. 409850/0763 2422A69 - Al - 10. Composition according to one of claims 7 to 9, in particular for use for road surfaces, characterized in that the hydrocarbon material contains a bitumen a penetration number of 80 to 100 and the mass in the cold has an equal or greater viscosity than bitumen alone and at temperatures of the order of 160 ° C has a much lower viscosity than bitumen. 11. Composition according to one of claims 7 to 10, characterized characterized that their cohesion at -33 C is at least 0.46 kg / cm. 12. Composition according to one of claims 7 to 11, characterized characterized that their cohesion at +55 ⁰ C is greater than 5 kg / cm. 409850/0763